QNX QNX Tahiti Category="Computing platforms"Category="Embedded operating systems"Category="Operating systems"Category="Real-time operating systems"Category="Unix"
QNX
[image]
QNX Desktop after installation.
Company/developer:QNX Software systems
OS family:Not Applicable
Source model:Closed source
Latest stable release:6.3.0 / date unknown
Kernel type:Microkernel
License:Proprietary
Working state:Current
Website: www.qnx.com

QNX (pronounced either Q-N-X or Q-nix) is a commercial POSIX-compliant Unix-like Real-time operating system, aimed primarily at the embedded systems market. It is probably the most successful Microkernel Operating system.

Description

As a microkernel-based OS, QNX is based on the idea of running most of the OS in the form of a number of small tasks, known as servers. This differs from more traditional monolithic kernels, in which the operating system is a single very large program comprised of a huge number of "parts" with special abilities. In the case of QNX, the use of a microkernel allows users (developers) to turn off any functionality they do not require without having to change the OS itself; instead, those servers are simply not run.

The system is quite small, fitting in a minimal fashion on a single floppy, and is considered to be both very fast and fairly "complete."

QNX Neutrino (2001) has been ported to a number of platforms and now runs on practically any modern CPU that is used in the embedded market. This includes the X86 family, MIPS, PowerPC, SH-4 and the closely related family of ARM, StrongARM and xScale CPUs.

A version for non-commercial use can be downloaded for free from the company web site.

History

Gordon Bell and Dan Dodge, students at the University of Waterloo in 1980, both took a standard Computer science course in operating system design, in which the students constructed a basic real-time kernel. Both were convinced there was a commercial need for such a system, and moved to Kanata, Ontario, (a high-tech area outside Ottawa) to start Quantum Software Systems that year. In 1982 the first version, QNX, was released for the Intel 8088 CPU.

One of QNX's first widespread uses was in the non-embedded world, when it was selected as the operating system for the Ontario education system's own computer design, the Unisys ICON. Over the years QNX was used mostly for "larger" projects, as its 44k kernel was too large to fit inside the single-chip computers of the era. The system garnered an enviable reputation for reliability and found itself in use running machinery in a number of industrial applications.

In the mid-1990s, Quantum realized that the market was rapidly moving towards the POSIX model and decided to rewrite the kernel to be much more compatible at a lower level. The result was QNX 4. This was available with an embeddable GUI called Photon microGUI as well as a QNX version of the X Window System. QNX 4 made porting Unix software much easier and removed many of the quirks of the earlier version.

Toward the end of the 1990s they decided to model a new version on Linux as much as possible, while retaining the microkernel architecture. This resulted in QNX Neutrino, which was released in 2001. This version typically ships with Momentics, an Integrated Development Environment(IDE) based on the Eclipse IDE, Various GNU tools, and Internet software including the Voyager web browser and server. The company also renamed itself QNX Software Systems in the early 1990s to eliminate confusion with other companies, primarily with the hard drive manufacturer of the same name.

Neutrino was slated to re-appear on the desktop as the basis of a new Amiga operating system. This idea apparently died after management changed the goals of the "new" Amiga.

In 2004 several prominent engineers left the company as rumors of restructring began to surface, most notably among these was Chris McKillop who acted as liason between the community and the company. His departure was seen as a sign of the company's move away from its user community.

Later in 2004 some of the rumors proved true as the company announced it had been sold to Harmon International. Since the purchase, the company has restricted the once free version of QNX, moving away from the community as it concentrates on large, coporate accounts.

The former name was Qunix, changed to QNX due to Trademark issues.

Cisco's IOS-XR (the next version of IOS), is based on QNX.

Competitors

Some important competitors in the embedded market are LynxOS, VxWorks, Linux, THEOS, Windows CE, and OS-9.

External links